Power supplies for desktop and mobile PCs contribute significantly to the overall size, heat and noise of a system. For example, a typical desktop PC intended for office includes a 250 W–300 W power supply (PSU). However, the actual power drawn by the system while running normal office desktop applications is typically 70–150 W, including a power supply loss of approximately 20–30%. If a PC could be delivered with, for example, a 150 W power supply, this would represent a saving in cost for the manufacturer, and a reduction in overall size of the power supply enabling smaller PCs. Alternatively, with such a reduction in overall wattage for the PSU, a manufacturer could choose an external power supply further reducing volume, heat and noise within the system.
Another example is notebooks, which tend to ship with large external power supplies that are designed to run the notebook in worst case scenarios, making them bulky and cumbersome when traveling. If the power supply was matched to the actual consumption of the system, then a much smaller supply could be provided or offered as a option. A typical notebook may have a 45 W power supply, yet the same notebook is able to run for 2 hours on a 25 WH battery, thus if managed properly, a very small 15 W power supply could provide adequate power to run the notebook.
Another related problem is efficiency. Because power supplies are designed to operate at maximum efficiency when under the maximum rated load, if that load is decreased, the efficiency decreases as well. When efficiency is lowered, unnecessary heat is generated through losses in the PSU. By decreasing the maximum rating of the PSU, efficiency increases at lower loads, thus reducing heat.
Thus, there is a need for an improved system for managing power consumption within a PC that will allow manufacturers to build PCs having smaller, more efficient power supplies that better represent the actual power demands of PCs. The present invention provides such a solution.